Comparing the light sensitivity levels of various brands of surveillance
cameras

Identifying the components contained in a security control panel

A home security and surveillance system is an essential part of any modern
automated home. The basic design of a security system begins with analyzing
the needs of the inhabitants, surveying existing technology and hardware, reviewing
system costs, considering monitoring choices, and finally planning the installation.

In addition to perimeter and interior protection offered by a security system,
surveillance monitoring includes features that enable the inhabitants to observe
environmental conditions inside and outside the home when at home or away.

In a home surveillance system, video cameras and display systems are considered
by most contractors to be optional items. Subject to the homeowner's choice,
surveillance equipment can function independently from the basic features included
in home security monitoring.

This chapter provides the information you will need to know as a home integrator
for designing, integrating, and installing a home security and surveillance
system.

Design Considerations

The design of a security and surveillance system should provide for the
protection of the entire perimeter of a home as well as visual- and audio-based
surveillance monitoring. Security system sensors are available that are designed
to detect sound, window and door intrusion, air movement, body heat, motion, and
other conditions that indicate an intruder is present. A good security system
design should consider the best plan for existing homes as well as new
construction. It should also consider the lifestyle of all the inhabitants, the
location of valuables or any items to be protected, how the system is to be
controlled, adequate smoke and fire alerting sensors, and the type of emergency
response required. The design choices are numerous and varied due to advances in
home security technology and the wide availability of compact, low-cost video
surveillance systems.

Wireless Security Systems

Wireless home security systems use battery-powered radio transmitters and
receivers to connect the various components such as cameras, sensors, area
motion detectors, sirens, central controllers, smoke/fire detectors, keypads,
and video displays. These types of security systems are usually available at a
local hardware store or on the Internet and are often designed for
do-it-yourself installation. The basic advantages of wireless security systems
are

Wireless systems are easy to installThey avoid the expensive
and time-consuming task of installing new wires in the walls of existing
homes.

Wireless systems enable you to take the components with you when
moving to a new location.

Wireless sensors are designed to transmit a unique identification code
to a controllerThe controller learns the identity of each sensor and
links it to an appropriate zone. Each sensor also transmits status information
such as battery voltage, condition of the sensor switch, and other diagnostic
messages.

Some homeowner-installed wireless security systems can be set up to
record a voice message and to call programmed numbers in the event of an
alarmThis saves the cost of a professional monitoring
service.

Wireless sensors, motion detectors, and video cameras can often be
installed in locations that are not accessible for wired equipment.

The basic disadvantages of wireless security systems are

Wireless system design specifications can limit the distance between
sensors, cameras, and the central controller.

Wireless systems can be vulnerable to electromagnetic interference (EMI)
in some locations.

They require periodic replacement of batteries.

Most professional builders recommend wireless systems as a last
choice.

Hard-wired Security and Surveillance Systems

Hard-wired security and surveillance systems use wires installed inside the
walls, attics, crawl spaces, and underground to connect the sensors to a central
controller. Surveillance cameras or microphones are also wired to speakers,
video switchers, and video display monitors. A hard-wired system design normally
uses power from the home AC power wiring as the primary source. A rechargeable
battery pack is used by the controller for backup during power outages. The main
components of a hard-wired system are similar to a wireless system but without
the radio receiver and transmitter components. They include a central control
panel, sensors, one or more keypads, motion detectors, smoke and fire sensors,
cameras, camera switchers, video displays, and sirens. The advantages for a
hard-wired security system are

Hard-wired security systems are considered by most contractors to be more
reliable than wireless systems.

Hard-wired systems are usually installed by a professional security
system contractor with warranties and maintenance support.

Hard-wired systems avoid the problem of EMI and radio range limitations
inherent in some wireless security systems.

The hard-wired components are usually less visible and more aesthetically
pleasing than wireless components.

Hard-wired systems do not depend on batteries except for power failure
backup protection.

The disadvantages of a hard-wired security system are

Hard-wired systems are more expensive than wireless systems.

Hard-wired systems are usually leased from the company that installs the
system. Unlike a wireless system, the hard-wired system remains an integral part
of the home. The components are not capable of being moved to another home when
the owner relocates.

Problems can arise in the installation of sensors in existing homes where
some areas are not accessible for pulling wires inside the walls.

Remote Access Systems

A remote access system provides the capability to monitor and control a home
security system from a location away from the home. A telephone call to the home
followed by a key number code allows the caller to obtain status information
concerning environmental and alarm system condition. Remote systems can also be
programmed to call a specific phone number when certain environmental conditions
exceed an established threshold. A special synthesized voice response system
provides the caller with an audible report. The caller, with proper coded
inputs, can also perform all the same control functions from a distant location
that are available on the keypad in the home.

Features of remote access systems vary among vendors, but most systems have
features similar to those listed here:

Monitoring and reporting temperature inside and outside the home

Reporting on any sensors that have exceeded preset thresholds

Reporting on the date and time of any alarm conditions that
existed

Monitoring loud noises that exceed a set time interval using a built-in
microphone in the home security system

Reporting the status of smoke alarms or heat sensors

Fire Detection Systems

Fire detection sensors are available in two categories called heat detectors
and smoke detectors. They operate on a principle of detecting heat rise or smoke
in the home and can be either hard-wired with voltage supplied by the AC power
wiring or battery operated. Most fire detectors currently available are powered
by 9-volt DC transistor radio batteries, 120-volt AC power wiring, or 120-volt
AC power with battery backup. Wired-in smoke detectors connected to a fire or
security system are usually powered by DC from the security panel. This gives
the detectors a natural battery backup in the event of a power failure. Common
voltages are 6v, 12v, and 24v DC with 12v DC being the most common.

Some 120v AC units have the capability to interconnect so that when one unit
activates, it causes the audible alarm in the other units to sound. Units can
also be purchased that have a relay output for connection to any security system
control panel or wireless transmitter. The most common types available in
hardware stores operate as independent sensors that are battery powered, are not
connected to the security system, and have their own audible alarm sounder. Heat
sensors operate using a different technology from smoke detectors. The basic
design features of each type are summarized in the following paragraph.

Heat Sensors and Smoke Detectors

Heat sensors are designed to detect a rapid rise in temperature. They
also have a feature that sets off an alarm when a fixed temperature is reached.
Smoke detectors do not react to heat but use one of two common sensor
designs to detect smoke. An ionization type of detector forms an
electrical path inside a small chamber with a very small amount of radioactive
material. When smoke enters the chamber, the particles attach themselves to the
ions and change the electrical current flow. A photoelectric type of
detector works by using a photoelectric cell and a light source. The light does
not usually reach the photoelectric cell, but when smoke is present the light is
dispersed and reaches the photoelectric cell, triggering the alarm. The main
difference between the two types is photoelectric types are more sensitive to
large particles and ionization types are more sensitive to small particles.
Modern home design should include at least one of each type. Smoke and heat
detectors should be located in each sleeping area and on each story of the home
and placed on the ceiling or on the wall 6''12'' from
the ceiling.

CAUTION

Remember that heat and smoke detectors operate on different types of
technology. Heat detectors react to abrupt changes and go into an alarm
condition when a temperature changes rapidly or reaches a fixed value. Smoke
alarms do not react to heat but go into an alarm condition when smoke enters the
sensor area. The two main types of smoke detectors are ionization and
photoelectric.

Environmental Monitoring

Environmental monitoring can be incorporated into the design of a home
security and surveillance system to monitor the status of specific conditions.
This might be applicable to rural homes, vineyard owners, farmers, fruit
growers, and ranchers. Environment monitoring includes the tracking and
measurement of external as well as internal parameters. The following are
examples of the types of environmental data that can be monitored with existing
sensor systems:

Inside and outside temperatures

Barometric pressure

Frost alarm

Minimum and maximum temperature memory

Temperature trend indicator

Humidity

Emergency Response Systems

An emergency response system is a valuable optional enhancement to a home
security system. A large number of designs are available from which to choose,
depending on the personal needs of members of the household.

A personal emergency response system is usually designed for elderly or
disabled individuals living alone who need to contact a doctor or relatives in
an emergency with a minimal number of actions. Systems are available
incorporating some or all of the following physical and functional features:

Emergency response requestsThese are initiated by the user
using a miniature wireless radio transmitter with a built-in help button carried
or worn as a pendant by the user. Transmitters are lightweight, battery-powered
devices activated by pressing one or two buttons.

A receiver console connected to the telephoneThis receives
radio signals from the user's transmitter and dials an emergency response
center number.

An emergency response centerThis is similar to an alarm
monitoring service except the personnel in an emergency response center are
experienced medical response personnel.

Temperature Sensors

Temperature sensors are used as one component of an environmental monitoring
and security system mentioned earlier. They are normally used to monitor high
and low temperature values in vacation homes, water pipes, furnace and heating
vents, outside farm buildings, computer equipment, utility rooms, or areas that
might sustain damage with extreme temperature swings.

Temperature sensors are often integrated with a central controller that
includes a display, a keypad, and an automatic telephone dialer that can alert
the homeowner or monitoring center when temperature limits are exceeded.
Temperature sensors use a variety of electronic designs and components to
measure temperature, including both analog and digital signal outputs that
change value with a change in temperature and operate remote switches or active
alarms.